From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3CCE2C433DF for ; Thu, 13 Aug 2020 16:32:11 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 00FA6206A4 for ; Thu, 13 Aug 2020 16:32:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Ehk83Rnn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 00FA6206A4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:49220 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k6G9C-0004mC-1E for qemu-devel@archiver.kernel.org; Thu, 13 Aug 2020 12:32:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55422) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k6G7A-0001x0-7G for qemu-devel@nongnu.org; Thu, 13 Aug 2020 12:30:04 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:34131 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1k6G77-0001EE-Kz for qemu-devel@nongnu.org; Thu, 13 Aug 2020 12:30:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597336201; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AfqQ+rA+QU47hCv+fgERdM5S2is2RvTloiHcD5kJKzc=; b=Ehk83Rnnazl/pViWh6YZijoVamoTMtpW1lT39TQFcQ/DqZZ3XSoDjkGu1lOo5mAooAR+Rr lFPD+mu3GuXJVRycLWxOoW4gbfREgXwpSjl3x6IWRP59N+YvlhrdTa+ZUiRjP4TONf2QBk soCEUyDDFxZ5dj0FuausqLEWdPamH1E= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-202-rtV3Yq1sMzmtJCuMQ52w5Q-1; Thu, 13 Aug 2020 12:29:59 -0400 X-MC-Unique: rtV3Yq1sMzmtJCuMQ52w5Q-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3AA991015DC0; Thu, 13 Aug 2020 16:29:58 +0000 (UTC) Received: from linux.fritz.box.com (ovpn-113-97.ams2.redhat.com [10.36.113.97]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1D40F5C1BB; Thu, 13 Aug 2020 16:29:56 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Subject: [RFC PATCH 08/22] nbd: Add max-connections to nbd-server-start Date: Thu, 13 Aug 2020 18:29:21 +0200 Message-Id: <20200813162935.210070-9-kwolf@redhat.com> In-Reply-To: <20200813162935.210070-1-kwolf@redhat.com> References: <20200813162935.210070-1-kwolf@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=kwolf@redhat.com X-Mimecast-Spam-Score: 0.001 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=205.139.110.120; envelope-from=kwolf@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/13 03:44:21 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is a QMP equivalent of qemu-nbd's --share option, limiting the maximum number of clients that can attach at the same time. Signed-off-by: Kevin Wolf --- qapi/block-export.json | 10 ++++++++-- include/block/nbd.h | 3 ++- block/monitor/block-hmp-cmds.c | 2 +- blockdev-nbd.c | 33 ++++++++++++++++++++++++++------- qemu-storage-daemon.c | 4 ++-- 5 files changed, 39 insertions(+), 13 deletions(-) diff --git a/qapi/block-export.json b/qapi/block-export.json index 40369814b4..1fdc55c53a 100644 --- a/qapi/block-export.json +++ b/qapi/block-export.json @@ -14,6 +14,8 @@ # is only resolved at time of use, so can be deleted and # recreated on the fly while the NBD server is active. # If missing, it will default to denying access (since 4.0). +# @max-connections: The maximum number of connections to allow at the same +# time, 0 for unlimited. (since 5.2; default: 0) # # Keep this type consistent with the nbd-server-start arguments. The only # intended difference is using SocketAddress instead of SocketAddressLegacy. @@ -23,7 +25,8 @@ { 'struct': 'NbdServerOptions', 'data': { 'addr': 'SocketAddress', '*tls-creds': 'str', - '*tls-authz': 'str'} } + '*tls-authz': 'str', + '*max-connections': 'uint32' } } ## # @nbd-server-start: @@ -40,6 +43,8 @@ # is only resolved at time of use, so can be deleted and # recreated on the fly while the NBD server is active. # If missing, it will default to denying access (since 4.0). +# @max-connections: The maximum number of connections to allow at the same +# time, 0 for unlimited. (since 5.2; default: 0) # # Returns: error if the server is already running. # @@ -51,7 +56,8 @@ { 'command': 'nbd-server-start', 'data': { 'addr': 'SocketAddressLegacy', '*tls-creds': 'str', - '*tls-authz': 'str'} } + '*tls-authz': 'str', + '*max-connections': 'uint32' } } ## # @BlockExportOptionsNbd: diff --git a/include/block/nbd.h b/include/block/nbd.h index ffca3be78f..6fc1f05ef4 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -352,7 +352,8 @@ void nbd_client_get(NBDClient *client); void nbd_client_put(NBDClient *client); void nbd_server_start(SocketAddress *addr, const char *tls_creds, - const char *tls_authz, Error **errp); + const char *tls_authz, uint32_t max_connections, + Error **errp); void nbd_server_start_options(NbdServerOptions *arg, Error **errp); /* nbd_read diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c index 56bc83ac97..a651954e16 100644 --- a/block/monitor/block-hmp-cmds.c +++ b/block/monitor/block-hmp-cmds.c @@ -411,7 +411,7 @@ void hmp_nbd_server_start(Monitor *mon, const QDict *qdict) goto exit; } - nbd_server_start(addr, NULL, NULL, &local_err); + nbd_server_start(addr, NULL, NULL, 0, &local_err); qapi_free_SocketAddress(addr); if (local_err != NULL) { goto exit; diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 019c37c0bc..28159a92b2 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -23,23 +23,41 @@ typedef struct NBDServerData { QIONetListener *listener; QCryptoTLSCreds *tlscreds; char *tlsauthz; + uint32_t max_connections; + uint32_t connections; } NBDServerData; static NBDServerData *nbd_server; +static void nbd_update_server_watch(NBDServerData *s); + static void nbd_blockdev_client_closed(NBDClient *client, bool ignored) { nbd_client_put(client); + assert(nbd_server->connections > 0); + nbd_server->connections--; + nbd_update_server_watch(nbd_server); } static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc, gpointer opaque) { + nbd_server->connections++; + nbd_update_server_watch(nbd_server); + qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server"); nbd_client_new(cioc, nbd_server->tlscreds, nbd_server->tlsauthz, nbd_blockdev_client_closed); } +static void nbd_update_server_watch(NBDServerData *s) +{ + if (!s->max_connections || s->connections < s->max_connections) { + qio_net_listener_set_client_func(s->listener, nbd_accept, NULL, NULL); + } else { + qio_net_listener_set_client_func(s->listener, NULL, NULL, NULL); + } +} static void nbd_server_free(NBDServerData *server) { @@ -88,7 +106,8 @@ static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) void nbd_server_start(SocketAddress *addr, const char *tls_creds, - const char *tls_authz, Error **errp) + const char *tls_authz, uint32_t max_connections, + Error **errp) { if (nbd_server) { error_setg(errp, "NBD server already running"); @@ -96,6 +115,7 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, } nbd_server = g_new0(NBDServerData, 1); + nbd_server->max_connections = max_connections; nbd_server->listener = qio_net_listener_new(); qio_net_listener_set_name(nbd_server->listener, @@ -120,10 +140,7 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, nbd_server->tlsauthz = g_strdup(tls_authz); - qio_net_listener_set_client_func(nbd_server->listener, - nbd_accept, - NULL, - NULL); + nbd_update_server_watch(nbd_server); return; @@ -134,17 +151,19 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, void nbd_server_start_options(NbdServerOptions *arg, Error **errp) { - nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz, errp); + nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz, + arg->max_connections, errp); } void qmp_nbd_server_start(SocketAddressLegacy *addr, bool has_tls_creds, const char *tls_creds, bool has_tls_authz, const char *tls_authz, + bool has_max_connections, uint32_t max_connections, Error **errp) { SocketAddress *addr_flat = socket_address_flatten(addr); - nbd_server_start(addr_flat, tls_creds, tls_authz, errp); + nbd_server_start(addr_flat, tls_creds, tls_authz, max_connections, errp); qapi_free_SocketAddress(addr_flat); } diff --git a/qemu-storage-daemon.c b/qemu-storage-daemon.c index b6f678d3ab..0fcab6ed2d 100644 --- a/qemu-storage-daemon.c +++ b/qemu-storage-daemon.c @@ -101,9 +101,9 @@ static void help(void) " configure a QMP monitor\n" "\n" " --nbd-server addr.type=inet,addr.host=,addr.port=\n" -" [,tls-creds=][,tls-authz=]\n" +" [,tls-creds=][,tls-authz=][,max-connections=]\n" " --nbd-server addr.type=unix,addr.path=\n" -" [,tls-creds=][,tls-authz=]\n" +" [,tls-creds=][,tls-authz=][,max-connections=]\n" " start an NBD server for exporting block nodes\n" "\n" " --object help list object types that can be added\n" -- 2.25.4